1. Field of Invention
The invention relates to a vehicular parking brake apparatus.
2. Description of Related Art
A vehicular parking brake apparatus is described in Japanese Utility Model Application Laid-Open No. HEI 5-44739. In the parking brake apparatus described in the laid-open application, a parking brake is operated in association with an operation of a service brake operating member if a servo device of a service brake apparatus has failed. Therefore, the short fall in the braking force on wheels can be reduced.
However, for example, if the vehicle is running on a low-friction road, a case may occur in which the braking force becomes excessively great compared with the friction coefficient of the road surface. Thus, the slip rate of a wheel may become excessively great.